Global Patent Index - EP 0113032 B1

EP 0113032 B1 19880713 - AN APPARATUS FOR PERFORMING HASHING OPERATIONS USING GALOIS FIELD MULTIPLICATION

Title (en)

AN APPARATUS FOR PERFORMING HASHING OPERATIONS USING GALOIS FIELD MULTIPLICATION

Publication

EP 0113032 B1 19880713 (EN)

Application

EP 83111762 A 19831124

Priority

US 45491282 A 19821230

Abstract (en)

[origin: EP0113032A2] The invention comprises an apparatus for performing a hashing operation on an N bit number under control of a prespecified N bit hashing constant which comprises performing N/K finite field partial multiplications of the object to be hashed by the hashing constant, utilizing K logic and combinatorial circuits (FSR1, 10 FSR2, 12..) all of which operate in parallel to completely evalute the function in N/K operations.Another feature of the present invention is that the hashing constant loaded into the system may be changed at will-with a resultant changing of the hashing characteristics to suit a particular class of objects to be hashed. This is done by a "select" operation. In the "select" operation, the hashing constant is sequentially loaded into said K logic and combinatorial circuits, each of which comprises a feedback shift register (FSR1,...K), said feedback shift registers being so configured that at the end of K operational sequences each of said feedback shift registers contains said hashing constant shifted and permuted in accordance with the particular feedback configuration of said register, a number of bits proportional to its location in the sequence of feedback shift registers, such that the hashing constant in the shift register FSR, will be shifted in a predetermined direction (i-1) N/K bit positions. Each of the operational sequences referred to above comprises a hashing sequence which includes N/K shifts of the feedback shift registers.

IPC 1-7

G06F 15/40

IPC 8 full level

G06F 17/30 (2006.01)

CPC (source: EP US)

G06F 16/9014 (2018.12 - EP US)

Designated contracting state (EPC)

DE FR GB

DOCDB simple family (publication)

EP 0113032 A2 19840711; EP 0113032 A3 19851030; EP 0113032 B1 19880713; DE 3377389 D1 19880818; JP H0243218 B2 19900927; JP S59125437 A 19840719; US 4538240 A 19850827

DOCDB simple family (application)

EP 83111762 A 19831124; DE 3377389 T 19831124; JP 17234683 A 19830920; US 45491282 A 19821230